I have been having some issues with my 1998 Ranger XLT 4x4 Off-Road 4.0 EFI. For a while now it has been idling low, especially when I try to start it when it is warm. My mechanic suggested cleaning the throttle body with carb cleaner. He did it once and it seemed to work for a little while, but then it got worse. I tried cleaning it myself and now it will hardly run, unless it is moving. Also there is a good chance that the little red straw that came with the carb cleaner is somewhere in my throttle body or combustion chamber.

Right now when I start it the rpms start normal for a second then dip to almost nothing, then jump up, then dip etc. Only now the engine will cut if I am stopped and I don't apply a little gas. What should I do, the local shop can't look at it until Tuesday and I use my truck every day.

BTW the truck runs fine when I am cruising above 40 mph. When I let off the gas the rpms drop.

I know that it is not the battery, I had it checked.

Please advise.

 

Check the IAC - idle air control

With the truck being that old, it might need cleaning
Or replacing.

 

Look for the straw!

And read thru this thread.

https://www.ford-trucks.com/forums/1...rol-valve.html

 

I looked and looked and looked for the star in the throttle body, in the engine compartment, and in the ground underneath. What are the odds and consequences if the straw ends up in a cylinder?

Tried cleaning the iac (that's how I lost the straw), going to get a replacement asap.

I will keep you posted. Let Let me know about the straw.

 

Be sure you use a plastic safe cleaner, not carb cleaner. Both your truck and your wallet will thank you. The carb cleaner will remove the coating in the air intake system, allowing it to get gummed up fairy quickly.

 

New IAC valve did the trick. Idles like a champ now. Thanks guys. I am still concerned about the straw. What wipl happen if the straw is in there?

 

Interesting thread. I'm learning lots!